const xss = require('xss')
const { exec } = require('../db/mysql')

const getList = (author, keyword) => {
    let sql = `select * from blogs where 1=1 `

    if (author) {
        sql += `and author='${author}' `
    }

    if (keyword) {
        sql += `and title like '%${keyword}%' `
    }

    sql += `order by createtime desc;`

    // 返回 promise
    return exec(sql)
}

const getDetail = (id) => {
    const sql = `select * from blogs where id='${id}'`
    return exec(sql).then(rows => {
        return rows[0]
    })
}

const newBlog = (blogData = {}) => {
    //blogData是一个博客对象，包含 title content author createtime属性
    const title = xss(blogData.title)
    const content = xss(blogData.content)
    const author = blogData.author
    const createtime = Date.now()

    const sql = `
        insert into blogs (title, content, createtime, author)
        values ('${title}', '${content}', ${createtime}, '${author}');
    `
    return exec(sql).then(inserrtData => {
        return {
            id: inserrtData.insertId
        }
    })
}

const updateBlogData = (id, blogData = {}) => {
    //id 要更新博客的id
    //blogData是一个博客对象，包含 title content 属性
    const title = blogData.title
    const content = blogData.content
    const sql = `
        update blogs set title='${title}', content='${content}' where id=${id}
    `

    return exec(sql).then(updateData => {
        if (updateData.affectedRows > 0) {
            return true
        }

        return false
    })
}

const delBlog = (id, author) => {
    const sql = `delete from blogs where id=${id} and author='${author}'`

    return exec(sql).then(delData => {
        if (delData.affectedRows > 0) {
            return true
        }

        return false
    })
}

module.exports = {
    getList,
    getDetail,
    newBlog,
    updateBlogData,
    delBlog
}